Components having a surface micromechanical structure, in which both the insulation layer applied to the substrate and the sacrificial layer are implemented in the form of a silicon oxide layer, are known from industrial practice. To expose the movable elements of the surface micromechanical structure, silicon oxide is removed at least in the areas under the movable elements, an HF etching medium being typically used for this purpose. However, other portions of the component structure are usually also undercut at this time, since this etching method is a purely time-controlled, isotropic process without a design-controlled etch stop.
Components having a layer structure, such as described above, have presented problems in several aspects. Thus, it is only possible to ensure the mechanical fastening of immovable elements of the surface micromechanical structure of such a component if these elements have certain minimum dimensions, so that they are not fully undercut and thus detached from the substrate when the sacrificial layer is etched. Problems in the electrical connection of the component's functional layer may also occur. Electrodes, which are designed as immovable elements in the surface micromechanical structure, are often electrically contacted via a structured printed conductor layer situated between the insulation layer applied to the substrate and the sacrificial layer. If the insulation layer and the sacrificial layer are made of the same material, namely silicon oxide, at least the edge areas of the structured printed conductor layer are normally undercut when the sacrificial layer is etched. Contaminant particles may then easily be deposited on or embedded in these areas, causing a short-circuit to the substrate.